Method for detecting synchronization signal block, and method, apparatus and system for transmitting synchronization signal block

ABSTRACT

The present disclosure is related to a terminal device and a network device. The terminal device includes: a receiver configured to receive a first synchronization signal block transmitted by an access network device, wherein the first synchronization signal block comprises a physical broadcast channel (PBCH); and a processor configured to determine a location of a frequency resource of a second synchronization signal block according to preset information comprised in the physical broadcast channel (PBCH), wherein the first synchronization signal block and the second synchronization signal block carry same information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/467,949, filed Jun. 7, 2019, which is a U.S. national phase entry ofInternational Application No. PCT/CN2017/077142, filed Mar. 17, 2017,the entire disclosures of which are incorporated herein by reference intheir entireties.

TECHNICAL FIELD

Embodiments of the present disclosure relate to the field ofcommunications, and in particular, to a method for detecting asynchronization signal block, and a method, a device and a system fortransmitting synchronization signal block.

BACKGROUND

In a long-term evolution (LTE) system, a base station transmits asynchronization signal by using an omni-directional transmissiontechnology, so that a terminal establishes synchronization with the basestation according to the synchronization signal, and accesses the cell.

In a 5th generation mobile communication (5G) system, since the basestation and the terminal use a high frequency band of 6 GHz or higher,the base station will send a signal by means of a beam scanning in orderto solve a problem of high frequency signal poor coverage and largeattenuation. Therefore, in the 5G system, the base station will usedifferent beams to transmit a synchronization signal block (SS Block) indifferent beam scanning directions. The synchronization signal blockincludes a primary synchronization signal (PSS), a secondarysynchronization signal (SSS), and a synchronization channel. After theterminal receives the synchronization signal block from thecorresponding beam scanning direction, the terminal detects thesynchronization signal block, and then completes synchronization andaccesses the cell.

In order to improve access performance of the terminal, the terminalneeds to perform joint detection on the synchronization signal blocksincluding same information. However, in related arts, since the terminalcannot identify the synchronization signal blocks including the sameinformation, the joint detection cannot be performed, thereby affectingthe access performance of the terminal.

SUMMARY

Embodiments of the present disclosure provide a method for detecting asynchronization signal block, and a method, device and system fortransmitting synchronization signal block. The technical solutions areas follows:

According to a first aspect of embodiments of the present disclosure, amethod for detecting a synchronization signal block is provided. Themethod includes:

receiving, by a terminal, a first synchronization signal blocktransmitted by an access network device;

determining, by the terminal, a location of a time-frequency resource ofa second synchronization signal block according to preset informationincluded in the first synchronization signal block, wherein the firstsynchronization signal block and the second synchronization signal blockare sent using a same beam, or the first synchronization signal blockand the second synchronization signal block carry same information; and

detecting, by the terminal, the second synchronization signal block.

In an optional embodiment, the preset information includes:

a total amount of different beams used when the access network devicetransmits synchronization signal blocks; and/or a transmission period ofsynchronization signal blocks.

In an optional embodiment, the preset information includes the totalamount of beams, and the transmission period is pre-agreed; or

the preset information includes the transmission period, and the totalamount of beam types is pre-agreed.

In an optional embodiment, determining the location of thetime-frequency resource of the second synchronization signal blockaccording to the preset information included in the firstsynchronization signal block includes:

calculating, by the terminal, a time domain interval between the firstsynchronization signal block and the second synchronization signal blockaccording to the total amount of beams and the transmission period; and

determining, by the terminal, a time domain location of the secondsynchronization signal block according to the time domain interval and atime domain location of the first synchronization signal block;

wherein the time domain interval is at least one of the number ofsub-frames, the number of slots, the number of mini-slots, or the numberof orthogonal frequency division multiplexing (OFDM) symbols.

In an optional embodiment, the preset information includes atransmission period of a synchronization signal block set where thefirst synchronization signal block is located, and the synchronizationsignal block set includes at least one group of synchronization signalblocks.

In an optional embodiment, determining the location of thetime-frequency resource of the second synchronization signal blockaccording to preset information comprised in the first synchronizationsignal block includes:

determining, by the terminal, the transmission period as the time domaininterval between the first synchronization signal block and the secondsynchronization signal block; and

determining, by the terminal, a time domain location of the secondsynchronization signal block according to the time domain interval and atime domain location of the first synchronization signal block;

wherein the time domain interval is at least one of the number ofsub-frames, the number of slots, the number of mini-slots, or the numberof orthogonal frequency division multiplexing (OFDM) symbols.

In an optional embodiment, the preset information includes a totalamount of synchronization signal blocks in the synchronization signalblock set where the first synchronization signal block is located, andthe synchronization signal block set includes at least one group ofsynchronization signal blocks.

In an optional embodiment, determining the location of thetime-frequency resource of the second synchronization signal blockaccording to the preset information included in the firstsynchronization signal block includes:

determining, by the terminal, the time domain interval between the firstsynchronization signal block and the second synchronization signal blockaccording to the total amount of synchronization signal blocks and apre-agreed transmission period of synchronization signal blocks; and

determining, by the terminal, a time domain location of the secondsynchronization signal block according to the time domain interval andthe time domain location of the first synchronization signal block;

wherein the time domain interval is at least one of the number ofsub-frames, the number of slots, the number of mini-slots, or the numberof orthogonal frequency division multiplexing (OFDM) symbols.

In an optional embodiment, the preset information includes a first timedomain index of the first synchronization signal block, and the firsttime domain index indicates a time domain location of the firstsynchronization signal block.

In an optional embodiment, the first time domain index is an index ofthe first synchronization signal block in a synchronization signal blockset;

or,

the first time domain index is an index of a time domain resource wherethe first synchronization signal block is located in a radio frame, asub-frame, or a time slot;

or,

the first time domain index is an index of all synchronization signalblocks where the first synchronization signal block is located in aradio frame, a sub-frame, or a time slot;

wherein the synchronization signal block set includes at least one groupof synchronization signal blocks, and the time domain resource is asub-frame, a time slot, a mini-slot or an orthogonal frequency divisionmultiplexing OFDM symbol.

In an optional embodiment, determining the location of thetime-frequency resource of the second synchronization signal blockaccording to preset information comprised in the first synchronizationsignal block includes:

calculating, by the terminal, a second time domain index correspondingto the second synchronization signal block according to the first timedomain index and a pre-agreed index interval; and

determining, by the terminal, a time domain location of the secondsynchronization signal block according to the second time domain index.

In an optional embodiment, the preset information includes a frequencydomain interval between the first synchronization signal block and thesecond synchronization signal block;

determining the location of the time-frequency resource of the secondsynchronization signal block according to preset information included inthe first synchronization signal block further includes:

determining, by the terminal, a frequency domain location of the secondsynchronization signal block according to a frequency domain location ofthe first synchronization signal block and the frequency domain intervalbetween the first synchronization signal block and the secondsynchronization signal block.

In an optional embodiment, detecting the second synchronization signalblock includes:

performing, by the terminal, joint detection of a first synchronizationsignal in the first synchronization signal block and a secondsynchronization signal in the second synchronization signal block;

or,

performing, by the terminal, joint detection of a first synchronizationchannel in the first synchronization signal block and a secondsynchronization channel in the second synchronization signal block;

or,

detecting, by the terminal, the second synchronization signal block byusing a receiving beam different from that of the first synchronizationsignal block.

In an optional embodiment, the first synchronization signal blockincludes the first synchronization signal and the first synchronizationchannel, and the first synchronization signal or the firstsynchronization channel includes the preset information.

According to a second aspect of the embodiments of the presentdisclosure, a method for transmitting a synchronization signal block isprovided. The method includes:

transmitting, by an access network device, a first synchronizationsignal block to a terminal; and

transmitting, by the access network device, a second synchronizationsignal block to the terminal, wherein the first synchronization signalblock and the second synchronization signal block are sent by a samebeam, or the first synchronization signal block and the secondsynchronization signal block carry same information;

wherein the first synchronization signal block includes presetinformation, and the terminal is configured to determine a location of atime-frequency resource of the second synchronization signal blockaccording to the preset information, and detect the secondsynchronization signal block.

In an optional embodiment, the preset information includes:

a total amount of different beams used when the access network devicetransmits synchronization signal blocks;

and/or,

a transmission period of synchronization signal blocks;

and/or,

a transmission period of a synchronization signal block set where thefirst synchronization signal block is located, and the synchronizationsignal block set includes at least one group of synchronization signalblocks;

and/or,

a total amount of synchronization signal blocks in a synchronizationsignal block set where the first synchronization signal block islocated, and the synchronization signal block set includes at least onegroup of synchronization signal blocks;

and/or,

a first time domain index of the first synchronization signal block,wherein the first time domain index indicates a time domain location ofthe first synchronization signal block;

and/or,

a frequency domain interval between the first synchronization signalblock and the second synchronization signal block.

According to a third aspect of the embodiments of the presentdisclosure, a device for detecting a synchronization signal block isprovided, including at least one unit configured to implement the methodfor detecting a synchronization signal block provided by the firstaspect or any one of the possible implementations of the first aspect.

According to a fourth aspect of the present disclosure, a device fortransmitting a synchronization signal block including at least one unitconfigured to implement the method for transmitting a synchronizationsignal block provided by the second aspect or any one of the possibleimplementations of the second aspect.

According to a fifth aspect of the embodiments of the presentdisclosure, a terminal is provided. The terminal includes a processor, amemory, a transmitter and a receiver; the memory is configured to storeone or more instructions to be executed by the processor, and theprocessor is configured to implement the method for detecting asynchronization signal block provided by the first aspect or any one ofthe possible implementations of the first aspect; the receiver isconfigured to receive the synchronization signal block, and thetransmitter is configured to transmit an uplink signal.

According to a sixth aspect of the embodiments of the presentdisclosure, an access network device is provided. The access networkdevice includes a processor, a memory, a transmitter and a receiver; thememory is configured to store one or more instructions to be executed bythe processor, and the processor is configured to implement the methodfor transmitting a synchronization signal block provided by the secondaspect or any one of the possible implementations of the second aspect;the receiver is configured to receive the uplink signal, and thetransmitter is configured to transmit the synchronization signal block.

According to a seventh aspect of the embodiments of the presentdisclosure, a mobile communication system is provided, including: aterminal and an access network device.

The terminal includes the device for detecting the synchronizationsignal block according to the third aspect;

the access network device includes the device for transmitting asynchronization signal block according to the fourth aspect.

According to an eighth aspect of the embodiments of the presentdisclosure, a mobile communication system is provided, including: aterminal and an access network device.

The terminal includes the terminal according to the fifth aspect;

the access network device includes the access network device accordingto the sixth aspect.

According to a ninth aspect of the embodiments of the presentdisclosure, a computer readable medium is provided, and the computerreadable medium stores one or more instructions configured to implementthe method for detecting a synchronization signal block provided by thefirst aspect or any one of the possible implementations of the firstaspect.

According to a tenth aspect of the embodiments of the presentdisclosure, a computer readable medium is provided, and the computerreadable medium stores one or more instructions configured to implementthe method for transmitting a synchronization signal block provided bythe second aspect or any one of the possible implementations of thesecond aspect.

The beneficial effects of the technical solutions provided by theembodiments of the present disclosure are as follows:

The access network device adds the preset information to thesynchronization signal block. After the terminal receives thesynchronization signal block, the terminal can determine, according tothe preset information, the location of a time-frequency resource ofother synchronization signal blocks which carry the same information asthat of the synchronization signal block or are sent using the same beamas the synchronization signal block. Thus, the present disclosure canperform joint detection of two synchronization signal blocks, therebyimproving the terminal's detection performance on the synchronizationsignal block.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in theembodiments of the present disclosure, the drawings used in thedescription of the embodiments will be briefly described below. It isapparent that the drawings in the following description show only someof the embodiments of the present disclosure, and other drawings may beobtained by those skilled in the art without departing from the scope ofthe present disclosure.

FIG. 1 is a schematic structural diagram of a mobile communicationsystem according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of an access network device transmitting asynchronization signal block by using beam scanning;

FIG. 3 is a flowchart of a method for detecting a synchronization signalblock according to an embodiment of the present disclosure;

FIG. 4 is a flowchart of a method for detecting a synchronization signalblock according to an embodiment of the present disclosure;

FIG. 5A is a flowchart of a method for detecting a synchronizationsignal block according to an embodiment of the present disclosure;

FIG. 5B is a schematic diagram of an access network device periodicallytransmitting a synchronization signal block set;

FIG. 6 is a flowchart of a method for detecting a synchronization signalblock according to an embodiment of the present disclosure;

FIG. 7 is a flowchart of a method for detecting a synchronization signalblock according to an embodiment of the present disclosure;

FIG. 8 is a schematic structural diagram of a device for detecting asynchronization signal block according to an embodiment of the presentdisclosure;

FIG. 9 is a schematic structural diagram of a terminal according to anexemplary embodiment of the present disclosure;

FIG. 10 is a schematic structural diagram of an access network deviceaccording to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

In order to make the objectives, technical solutions and advantages ofthe present disclosure more clear, the embodiments of the presentdisclosure will be further described in detail below with reference tothe accompanying drawings.

A “module” as referred to herein generally refers to program orinstruction(s) stored in a memory that is capable of performing certainfunctions; a “unit” as referred to herein generally refers to afunctional structure that is logically divided, and the “unit” can beimplemented by pure hardware or a combination of hardware and software.

“Multiple” as referred to herein means two or more. The expression“and/or” describes the association relationship of associated objectsand indicates that there may be three relationships. For example, Aand/or B may indicate that there are three cases: A exists only, A and Bexist at the same time, and B exists only. The character “/” generallyindicates that the contextual objects have an “or” relationship.

FIG. 1 is a schematic structural diagram of a mobile communicationsystem according to an embodiment of the present disclosure. The mobilecommunication system can be a 5G system, also known as a new radio (NR)system. The mobile communication system includes an access networkdevice 120 and a terminal 140.

The access network device 120 can be a base station, and the basestation can be configured to convert a received radio frame and areceived IP packet into each other, and can also coordinate attributemanagement of an air interface. For example, the base station may be anevolutional base station (eNB or e-NodeB, evolutional Node B) in LTE, ora base station using a central distributed architecture used in the 5Gsystem. When the access network device 120 adopts the centraldistributed architecture, it generally includes a central unit (CU) andat least two distributed units (DUs). Protocol stacks of a packet dataconvergence protocol (PDCP) layer, a radio link control (RLC) layer, anda medium access control (MAC) layer are provided in the central unit. Aprotocol stack of a physical layer (PHY) is provided in the distributedunits. The specific implementation of the access network device 120 isnot limited in the embodiments of the present disclosure.

The access network device 120 and the terminal 140 establish a wirelessconnection through a wireless air interface. According to an exemplaryembodiment, the wireless air interface is a wireless air interface basedon the fifth generation mobile communication network technology (5G)standards, for example, the wireless air interface is NR; or thewireless air interface may also be a wireless air interface based on anext generation mobile communication network technical standards that ismore advanced than 5G.

The terminal 140 may be a device that provides voice and/or dataconnectivity to a user. The terminal can communicate with one or morecore networks via a radio access network (RAN). The terminal 140 can bea mobile terminal, such as a mobile phone (or referred as a “cellular”phone) and a computer with the mobile terminal. For example, theterminal 140 can be a portable, pocket, handheld, computer built-in orin-vehicle mobile device, such as a subscriber unit a subscriberstation, a mobile station, a mobile, a remote station, an access point,a remote terminal, an access terminal, a user terminal, a user agent, auser device, or user equipment.

A method for detecting a synchronization signal block and a method fortransmitting synchronization signal block provided by variousembodiments of the present disclosure involve in a process for enablingthe terminal 140 initially to access the access network device 120.

It should be noted that, in the mobile communication system shown inFIG. 1, a plurality of access network devices 120 and/or a plurality ofterminals 140 may be included, and FIG. 1 shows an example where oneaccess network device 120 and one terminal 140 are included, andembodiments of the present do not impose specific limitations on this.

In the 5G system, in order to make a terminal that enters a range of acell successfully completes access, the access network device needs toperiodically transmit a synchronization signal block (SS Block). Afterthe terminal that enters the range of the cell receives thesynchronization signal block, that is, detects the synchronizationsignal block, a location of a time-frequency of the synchronizationsignal (including a primary synchronization signal and a secondarysynchronization signal)in the synchronization signal block isdetermined, and then the synchronization is completed according to thesynchronization signal. Further, the terminal determines thetime-frequency location of a synchronization channel in thesynchronization signal block, and then detects and demodulates thesynchronization channel, and finally completes cell access according toinformation carried in the synchronization channel (usually includingsystem information).

Different from the LTE system, the terminal and the access networkdevice in the 5G system both use a high frequency band of 6 GHz orhigher for signal transmission, the high frequency signal has thecharacteristics of large attenuation and poor coverage. Therefore, inorder to ensure quality of the terminal access, the access networkdevice in the 5G system transmits the synchronization signal blocks bymeans of beam scanning. Correspondingly, the terminal receives thesynchronization signal blocks transmitted by the access network deviceby means of a receiving beam, and then completes the access according tothe synchronization signal blocks.

For example, as shown in FIG. 2, for a cell covered by an access networkdevice (such as a 120° sector), the access network device uses fourdifferent beams to transmit the synchronization signal block. Forexample, a first beam is configured to scan a 0° to 30° region, a secondbeam is configured to scan a 30° to 60° region, a third beam isconfigured to scan a 60° to 90° region, and a fourth beam is configuredto scan a 90° to 120° region. The synchronization signal blockstransmitted by using four different beams constitute a synchronizationsignal block group; and in order to improve the terminal access rate,the access network device can repeatedly transmit the samesynchronization signal block group (the access network device repeatedlytransmits the group 3 times in FIG. 2). At least one synchronizationsignal block group may constitute a synchronization signal block set,and the synchronization signal block set is periodically transmitted. Inaddition, information carried in the synchronization signal blockstransmitted by using different beams may be different. For example, thesynchronization channels in different synchronization signal blockscarry different beam IDs, control channel information, and the like.

In order to improve the detection performance for the synchronizationsignal blocks, the terminal can perform joint detection of thesynchronization signal blocks carrying the same information. Forexample, as shown in FIG. 2, the terminal may perform joint detection ofthe synchronization signal blocks transmitted by the first beam (theinformation carried by the synchronization signal blocks transmitted bythe same beam is same) in the first synchronization signal block groupand the second synchronization signal block group. However, since theterminal cannot know which synchronization signal blocks carry the sameinformation and which synchronization signal blocks carry differentinformation, the terminal cannot perform joint detection of thesynchronization signal blocks, thereby affecting the detectionperformance for the synchronization signal blocks and the accessefficiency of the terminal.

In order to solve the above problem, in various embodiments of thepresent disclosure, the access network device adds the presetinformation into the synchronization signal block. After receiving thesynchronization signal block, the terminal can determine, according tothe preset information and the location of the time-frequency resourceof the current synchronization signal block, other synchronizationsignal blocks which carry the same information as that of thesynchronization signal block or are sent using the same beam as thesynchronization signal block. Thus, the present disclosure can performjoint detection of these synchronization signal blocks (i.e., thecurrent synchronization signal block and the other synchronizationblocks), thereby improving the detection performance of thesynchronization signal blocks and the access efficiency of the terminal.The present disclosure will be described as follows with illustrativeembodiments.

FIG. 3 is a flowchart of a method for detecting a synchronization signalblock according to an embodiment of the present disclosure. As anexample, the method for detecting a synchronization signal block isapplied to the mobile communication system shown in FIG. 1. The methodincludes the following steps:

In Step 301, the access network device transmits a first synchronizationsignal block to the terminal.

The first synchronization signal block includes at least a firstsynchronization signal and a first synchronization channel. Optionally,the first synchronization signal includes a primary synchronizationsignal and a secondary synchronization signal, and may further include abeam specific reference signal (BRS); the first synchronization channelis a physical broadcast channel (PBCH).

Before the access network device transmits the first synchronizationsignal block to the terminal, the preset information is added to thefirst synchronization signal block. Optionally, the firstsynchronization signal in the first synchronization signal blockincludes the preset information, or the first synchronization channel inthe first synchronization signal block includes the preset information.Optionally, the access network device uses different synchronizationsequences to indicate different preset information.

In Step 302, the terminal receives the first synchronization signalblock transmitted by the access network device.

Optionally, the terminal has at least one beam receiving direction, andthe terminal that enters the cell covered by the access network devicecan receive the first synchronization signal block from the at least onebeam receiving direction.

In Step 303, the terminal determines a location of a time-frequencyresource of a second synchronization signal block according to thepreset information included in the first synchronization signal block.The first synchronization signal block and the second synchronizationsignal block are sent using the same beam, or the first synchronizationsignal block and the second synchronization signal block carry the sameinformation.

Optionally, the terminal obtains the preset information from thesynchronization signal in the first synchronization signal block, orobtains the preset information from the first synchronization channel inthe first synchronization signal block.

Optionally, the preset information included in the first synchronizationsignal block includes at least one of the following.

1. A total amount of different beams used when the access network devicetransmits the synchronization signal block(s)

As an example, as shown in FIG. 2, the access network device transmits atotal of 16 synchronization signal blocks in a synchronization signalblock set, and uses four different beams, so the total amount of beamsis 4.

2. A transmission period of the synchronization signal block(s)

The transmission period of the synchronization signal block(s) is thelength of time between the transmissions of two adjacent synchronizationsignal blocks. The transmission period is in unit of a sub frame, aslot, a mini slot, an OFDM symbol, or the transmission period is anabsolute time.

3. A transmission period of the synchronization signal block set wherethe first synchronization signal block is located

Each synchronization signal block set includes a plurality ofsynchronization signal blocks. The synchronization signal block set isperiodically transmitted, and the synchronization signal blockstransmitted in the transmission periods of different synchronizationsignal block sets and the beams used are identical. For example, thesynchronization signal block set shown in FIG. 2 includes at least onegroup of synchronization signal blocks, and each synchronization signalblock in each group of synchronization signal blocks can be transmittedby using different beams.

As an example, the transmission period of the synchronization signalblock set(s) is the length of time between the transmissions of twoadjacent sets of synchronization signal blocks. The transmission periodis in unit of a sub frame, a slot, a mini slot, an OFDM symbol, or thetransmission period is an absolute time.

4. A total amount of the synchronization signal blocks in thesynchronization signal block set where the first synchronization signalblock is located

The synchronization signal block set includes at least one group ofsynchronization signal blocks, and synchronization signal blocks in eachgroup of synchronization signal blocks may be transmitted by usingdifferent beams.

As an example, as shown in FIG. 2, the synchronization signal block setwhere the first synchronization signal block is located includes a totalof 16 synchronization signal blocks, and the total amount of thesynchronization signal blocks is 16.

5. A first time domain index of the first synchronization signal block

The first time domain index indicates the time domain location of thefirst synchronization signal block.

6. A frequency domain interval between the first synchronization signalblock and the second synchronization signal block

When the access network device transmits the synchronization signalblocks in a frequency division multiplexing manner, frequency domainresources occupied by the first synchronization signal block and thesecond synchronization signal block may be different. Therefore, in apossible implementation, the preset information in the firstsynchronization signal block further includes the frequency domaininterval between the first synchronization signal block and the secondsynchronization signal block. The frequency domain interval is thenumber of physical resource blocks (PRB), the number of sub-bands orbandwidth, and the like.

After receiving the first synchronization signal block, the terminaldetermines a frequency domain location of the second synchronizationsignal block according to the frequency domain location of the firstsynchronization signal block and the frequency domain interval.

As an example, when the frequency domain interval included in the presetinformation of the first synchronization signal block is 60 kHz(bandwidth) and the frequency domain location of the firstsynchronization signal block is 1000 kHz, the frequency domain locationof the second synchronization signal block is 1060 kHz. In Step 304, theaccess network device transmits the second synchronization signal blockto the terminal.

The access network device transmits the second synchronization signalblock by using the same beam as that of the first synchronization signalblock. Optionally, the information carried by the first synchronizationsignal block is the same as the information carried in the secondsynchronization signal block.

As an example, as shown in FIG. 2, after transmitting the firstsynchronization signal block 21 (located in the first synchronizationsignal block group) to the terminal by using the first beam, the accessnetwork device transmits the second synchronization signal block 22(located in the second synchronization signal block group)to theterminal by using the first beam.

In Step 305, the terminal detects the second synchronization signalblock.

After receiving the second synchronization signal block at thedetermined time domain location, the terminal detects the secondsynchronization signal block.

For the detection process of the second synchronization signal block, ina possible implementation, the terminal performs a joint detection ofthe first synchronization signal in the first synchronization signalblock and the second synchronization signal in the secondsynchronization signal block, thereby improving the demodulationperformance of the terminal with regard to the synchronization signals.

In another possible implementation, the terminal performs a jointdetection of the first synchronization channel in the firstsynchronization signal block and the second synchronization channel inthe second synchronization signal block, thereby improving thedemodulation performance of the terminal with regard to thesynchronization signals.

Optionally, when performing the joint detection of the firstsynchronization channel and the second synchronization channel, theterminal combines soft bits in the first synchronization channel and thesecond synchronization channel to improve the detection performance.

In another possible implementation, the terminal detects the secondsynchronization signal block by using a receiving beam different fromthat of the first synchronization signal block.

As an example, the terminal has two types of receiving beams(corresponding to different beam receiving directions). After theterminal detects the first synchronizing signal block by using a firstreceiving beam, and determines the time domain location of the secondsynchronizing signal block according to the preset information in thefirst synchronizing signal block, the terminal detects the secondsynchronization signal block by using a second receiving beam. Further,according to the detection results of the first synchronization signalblock and the second synchronization signal block, the terminaldetermines the receiving beam corresponding to the optimal detectionresult as a target receiving beam, and receives a downlink signal byusing the target receiving beam during the process of receiving thedownlink signal subsequently. In summary, in the method for detecting asynchronization signal block provided by the embodiment, the accessnetwork device adds the preset information to the synchronization signalblock, so that after the terminal receives the synchronization signalblock, the terminal can determine, according to the preset information,the time-frequency resource locations of other synchronization signalblocks which carry the same information as the current synchronizationsignal block or other synchronization blocks that are transmitted byusing the same beam as that of the current synchronization signal block.Thus, the embodiment can implement joint detection of twosynchronization signal blocks, and improve the detection performance ofthe terminal with regard to the synchronization signal blocks.

In this embodiment, the terminal receives the first synchronizationsignal block and the second synchronization signal block by usingdifferent receiving beams to determine the target receiving beam withthe best receiving quality, and then the target receiving beam is usedto receive the subsequent downlink signals, and thus the receivingquality of the downlink signals is improved.

For the different types of preset information in the synchronizationsignal block, the terminal may use a corresponding determination modefor the time domain location, and determine the time domain location ofthe second synchronization signal block in view of the time domainlocation of the first synchronization signal block, and then detect thesecond synchronization signal block. In the embodiment shown in FIG. 4,the preset information includes the total amount of beams and/or atransmission period of the synchronization signal block. In theembodiment shown in FIG. 5A, the preset information includes atransmission period of the synchronization signal block set where thefirst synchronization signal block is located. In the embodiment shownin FIG. 6, the preset information includes the total amount of thesynchronization signal blocks in the synchronization signal block setwhere the first synchronization signal block is located. In theembodiment shown in FIG. 7, the preset information includes the firsttime domain index of the first synchronization signal block.

FIG. 4 is a flowchart of a method for detecting a synchronization signalblock according to another embodiment of the present disclosure. As anexample, the method for detecting a synchronization signal block may beapplied to the mobile communication system shown in FIG. 1. The methodincludes the following steps:

In Step 401, the access network device transmits the firstsynchronization signal block to the terminal. The preset information inthe first synchronization signal block includes a total amount ofdifferent beams used when the access network device transmitssynchronization signal blocks; and/or a transmission period ofsynchronization signal blocks.

In a possible implementation, the access network device addscorresponding preset information to the first synchronization signalblock based on the pre-agreed parameters in a protocol, so that theterminal can determine the time domain location of the secondsynchronization signal block according to the preset information and thepre-agreed parameters.

Optionally, when the transmission period of the synchronization signalblocks is pre-agreed in the protocol (the total amount of beams may beset by the access network device according to its own configuration),the preset information in the first synchronization signal blockincludes the total amount of different beams which the current accessnetwork device uses when transmitting synchronization signal blocks.

When the total amount of different beams used when the access networkdevice transmits the synchronization signal blocks is pre-agreed in theprotocol (the transmission period can be set by the access networkdevice), the transmission period of the synchronization signal blocks isincluded in the preset information in the first synchronization signalblock.

When the total amount of beams and the transmission period are notpre-agreed in the protocol, the total amount of beams and thetransmission period are both included in the preset information.

As an example, as shown in FIG. 2, when the transmission period of thesynchronization signal blocks is pre-agreed in the protocol as M OFDMsymbols, since the access network device uses four different beams whentransmitting the synchronization signal blocks, the preset informationin the first synchronization signal block includes the total amount ofbeams, i.e., N=4.

In Step 402, the terminal receives the first synchronization signalblock transmitted by the access network device.

The implementation of this step is similar to the foregoing step 302,and details are not described herein again.

In Step 403, the terminal calculates a time domain interval between thefirst synchronization signal block and the second synchronization signalblock according to the total amount of beams and the transmissionperiod.

The time domain interval is at least one of the number of sub-frames,the number of slots, the number of mini-slots, or the number oforthogonal frequency division multiplexing (OFDM) symbols.

In a possible implementation, the terminal calculates the time domaininterval according to the total amount of beams included in the presetinformation and the pre-agreed transmission period of synchronizationsignal blocks.

For example, if the total amount of beams included in the presetinformation obtained by the terminal is 4 and the pre-agreedtransmission period of the synchronization signal blocks is 8 OFDMsymbols, the time domain interval between the first synchronizationsignal block and the second synchronization signal block is 4×8=32 OFDMsymbols.

In another possible implementation, the terminal calculates the timedomain interval according to the transmission period included in thepreset information and the pre-agreed total amount of beams.

In Step 404, the terminal determines the time domain location of thesecond synchronization signal block according to the time domainlocation of the first synchronization signal block and time domaininterval.

Further, the terminal determines the time domain location of the secondsynchronization signal block according to the calculated time domaininterval and the time domain location of the first synchronizationsignal block.

As an example, as shown in FIG. 2, the time domain interval calculatedby the terminal according to the total amount of beams and thetransmission period is: the time domain interval between the firstsynchronization signal block 21 in the first synchronization signalblock group and the second synchronization signal block 22 in the secondsynchronization signal block group. Therefore, the terminal candetermine the time domain location of the second synchronization signalblock 22 if the time domain location of the first synchronization signalblock 21 and the time domain interval are known.

In Step 405, the access network device transmits the secondsynchronization signal block to the terminal.

The implementation of this step is similar to the foregoing step 304,and details are not described herein again.

In Step 406, the terminal receives the second synchronization signalblock from the determined time domain location.

Specifically, the terminal receives the synchronization signal block atthe time domain location according to the determined time domainlocation of the second synchronization signal block. The firstsynchronization signal block and the second synchronization signal blockare transmitted by using the same beam, or carry the same information.

In Step 407, the terminal detects the second synchronization signalblock.

The implementation of this step is similar to the foregoing step 305,and details are not described herein again.

In summary, in the method for detecting the synchronization signal blockprovided by the embodiment, the access network device adds the presetinformation to the synchronization signal block. After the terminalreceives the synchronization signal block, the terminal can determine,according to the preset information, the location of a time-frequencyresource of other synchronization signal blocks which carry the sameinformation as that of the synchronization signal block or are sentusing the same beam as the synchronization signal block. Thus, thepresent disclosure can perform joint detection of two synchronizationsignal blocks, thereby improving the terminal's detection performance onthe synchronization signal block.

FIG. 5A shows a flowchart of a method for detecting a synchronizationsignal block according to another embodiment of the present disclosure.As an example, the synchronization signal block detecting method isapplied to the mobile communication system shown in FIG. 1. The methodincludes the following steps:

In Step 501, the access network device transmits the firstsynchronization signal block to the terminal. The preset information inthe first synchronization signal block includes a transmission period ofthe synchronization signal block set where the first synchronizationsignal block is located.

In a possible implementation, in the synchronization signal block settransmitted by the access network device, the synchronization signalblocks are transmitted after using different beamforming manners, or theinformation carried by synchronization signal blocks is different (i.e.,the synchronization signal block set includes only one synchronizationsignal block group). In order to enable the terminal to perform jointdetection of the first synchronization signal block and the secondsynchronization signal block in the two adjacent synchronization signalblock sets, the access network device adds the transmission period ofthe synchronization signal block set to the first synchronization signalblock.

As an example, as shown in FIG. 5B, the access network deviceperiodically transmits the synchronization signal block sets, and eachof the synchronization signal block sets includes synchronization signalblocks that are beamformed using four types of beams. Thesynchronization signal block 51 transmitted by the access network deviceto the terminal includes the transmission period of the firstsynchronization signal block set which the synchronization signal block51 is in, and the transmission period is the time domain resourceoccupied by the complete transmission of the 4 synchronization signalblocks (including the interval between the adjacent synchronizationsignal blocks). For example, the transmission period is M time slots.

In Step 502, the terminal receives the first synchronization signalblock transmitted by the access network device.

In Step 503, the terminal determines the transmission period as the timedomain interval between the first synchronization signal block and thesecond synchronization signal block.

Since the synchronization signal block set is periodically transmitted,and the synchronization signal blocks included in the differentsynchronization signal block sets are the same, the terminal directlydetermines the transmission period as the time domain interval betweenthe first synchronization signal block and the second synchronizationsignal block.

As an example, as shown in FIG. 5B, when the transmission period is Mtime slots, the time domain interval between the synchronization signalblock 51 in the first synchronization signal block set and thesynchronization signal block 52 in the second synchronization signalblock set is M time slots.

In Step 504, the terminal determines the time domain location of thesecond synchronization signal block according to the time domainlocation of the first synchronization signal block and the time domaininterval.

Similarly to the above step 404, the terminal determines the time domainlocation of the second synchronization signal block in the adjacentsynchronization signal block sets according to the time domain locationof the first synchronization signal block and the time domain interval.

In Step 505, the access network device transmits the secondsynchronization signal block to the terminal.

In Step 506, the terminal receives the second synchronization signalblock from the determined time domain location.

In Step 507, the terminal detects the second synchronization signalblock.

The implementation of the foregoing steps 505 to 507 is similar to thesteps 405 to 407, and details are not described herein again.

FIG. 6 is a flowchart of a method for detecting a synchronization signalblock according to still another embodiment of the present disclosure.As an example, the synchronization signal block detecting method isapplied to the mobile communication system shown in FIG. 1. The methodincludes the following steps:

In Step 601, the access network device transmits the firstsynchronization signal block to the terminal. The preset information inthe first synchronization signal block includes a total amount ofsynchronization signal blocks in the synchronization signal block setwhere the first synchronization signal block is located.

In the embodiment shown in FIG. 5A, the access network device directlyadds the transmission period of the synchronization signal block set tothe first synchronization signal block. In another possibleimplementation, when the transmission period of the synchronizationsignal block is pre-agreed in the protocol, the access network devicemay only add the total amount of synchronization signal blocks in thesynchronization signal block set to the first synchronization signalblock, and the terminal calculates and obtains the transmission periodof the synchronization signal block according to the transmission periodof the synchronization signal block and the total amount ofsynchronization signal blocks.

For example, as shown in FIG. 2, the total amount of synchronizationsignal blocks included in the preset information in the firstsynchronization signal block is 16; for another example, as shown inFIG. 5B, the total amount of synchronization signal blocks included inthe preset information in the first synchronization signal block is 4.

In Step 602, the terminal receives the first synchronization signalblock transmitted by the access network device.

In Step 603, the terminal determines the time domain interval betweenthe first synchronization signal block and the second synchronizationsignal block according to the total amount of synchronization signalblocks and the pre-agreed transmission period of the synchronizationsignal block.

After receiving the first synchronization signal block, the terminalcalculates the transmission period of the synchronization signal blockset where the first synchronization signal block is located according tothe total amount of synchronization signal blocks and the pre-agreedtransmission period of the synchronization signal block, and determinesthe transmission period as the time domain interval between the firstsynchronization signal block and the second synchronization signal blockin the two adjacent synchronization signal block sets.

As an example, as shown in FIG. 5B, when the total amount ofsynchronization signal blocks included in the preset information is 4,and the pre-agreed transmission period of the synchronization signalblock is 1 time slot, the time domain interval between thesynchronization signal block 51 and the synchronization signal block 52(located in two adjacent synchronization signal block sets) is 4 timeslots.

In Step 604, the terminal determines the time domain location of thesecond synchronization signal block according to the time domainlocation of the first synchronization signal block and the time domaininterval.

In Step 605, the access network device transmits the secondsynchronization signal block to the terminal.

In Step 606, the terminal receives the second synchronization signalblock from the determined time domain location.

In Step 607, the terminal detects the second synchronization signalblock.

The implementation of the foregoing steps 605 to 607 is similar to thesteps 405 to 407, and details are not described herein again.

FIG. 7 is a flowchart of a method for detecting a synchronization signalblock according to still another embodiment of the present disclosure.As an example, the synchronization signal block detecting method is tothe mobile communication system shown in FIG. 1. The method includes thefollowing steps:

In Step 701, the access network device transmits the firstsynchronization signal block to the terminal. The preset information inthe first synchronization signal block includes a first time domainindex of the first synchronization signal block, where the first timedomain index indicates the time domain location of the firstsynchronization signal block.

In a first possible implementation, the first time domain index is anindex of the first synchronization signal block in the synchronizationsignal block set, and the synchronization signal block set includes atleast one synchronization signal block group.

As an example, as shown in FIG. 2, since the synchronization signalblock set includes 16 synchronization signal blocks, the time domainindexes of the respective synchronization signal blocks are 0 to 15.

In a second possible implementation, the first time domain index is anindex of a time domain resource where the first synchronization signalblock is located in a radio frame, a sub-frame, or a time slot. The timedomain resource is a sub-frame, a time slot, a mini slot or an OFDMsymbol.

For example, when the first synchronization signal block occupies afirst sub-frame of to radio frame (including a total of 10 sub-frames),the time domain index of the first synchronization signal block is 0. Asanother example, when the first synchronization signal block occupies athird sub-frame of the radio frame (including a total of 10 sub-frames),the time domain index of the first synchronization signal block is 2.

In a third possible implementation, the first time domain index is anindex of all synchronization signal blocks where the firstsynchronization signal block is located in a radio frame, a sub-frame,or a time slot.

For example, when a radio frame includes four synchronization signalblocks, and the four synchronization signal blocks occupy the first,third, fifth, and seventh sub-frames, respectively, the time domainindex of the synchronization signal block occupying the first sub-frameis 0, the time domain index of the synchronization signal blockoccupying the third sub-frame is 1, the time domain index of thesynchronization signal block occupying the fifth sub-frame is 2, and thetime domain index of the synchronization signal block occupying theseventh sub-frame is 3.

It should be noted that, in addition to the foregoing three settingmodes of the time domain index, the access network device may also set atime domain index for the synchronization signal block in other possiblemanners, which is not limited by the present disclosure.

In Step 702, the terminal receives the first synchronization signalblock transmitted by the access network device.

In Step 703, the terminal calculates a second time domain indexcorresponding to the second synchronization signal block according tothe first time domain index and the pre-agreed index interval.

The index interval indicates the difference of between the time domainindexes of the synchronization signal blocks transmitted by the samebeam, or indicates the difference between the time domain indexes of thesynchronization signal blocks carrying the same information.

As an example, as shown in FIG. 2, when the time domain index is anindex of the synchronization signal block in the synchronization signalblock set, the terminal calculates the second time domain index of thesecond synchronization signal block 22 as 0+4=4 according to the firsttime domain index 0 of the first synchronization signal block 21 and theindex interval 4 (the four synchronization signal blocks are in agroup).

In Step 704, the terminal determines the time domain location of thesecond synchronization signal block according to the second time domainindex.

For example, when the time domain index is an index of thesynchronization signal block in the synchronization signal block set,and the second time domain index is calculated as 4, the terminaldetermines the synchronization signal block corresponding to the timedomain index “4” as the second synchronization signal block.

In Step 705, the access network device transmits the secondsynchronization signal block to the terminal.

In Step 706, the terminal receives the second synchronization signalblock from the determined time domain location.

In Step 707, the terminal detects the second synchronization signalblock.

The implementation of the foregoing steps 705 to 707 is similar to thesteps 405 to 407, and details are not described herein again.

It should be noted that the steps performed by the terminal in the abovevarious embodiments may be separately implemented as the method fordetecting the synchronization signal block on the terminal side; and thesteps performed by the access network device in the above variousembodiments may be separately implemented as the method for transmittingthe synchronization signal block on the access network device side.

The following are device embodiments of the present disclosure. For theparts that are not elaborated in the device embodiments, reference maybe made to the technical details disclosed in the foregoing methodembodiments.

FIG. 8 is a schematic structural diagram of a device for detecting thesynchronization signal block according to an embodiment of the presentdisclosure. The device for detecting the synchronization signal blockcan be implemented as all or part of the terminal by software, hardware,or a combination of both software and hardware. The device for detectingthe synchronization signal block includes: a receiving unit 820, adetermining unit 840, and a detecting unit 860.

The receiving unit 820 is configured to implement the foregoing steps302, 402, 502, 602, and 702 and functions related to the receivingsteps.

The determining unit 840 is configured to implement the functions of theforegoing steps 303, 403 to 404, 503 to 504, 603 to 604, and 703 to 704.

The detecting unit 860 is configured to implement the function of theforegoing steps 305, 407, 507, and 607 and functions related to thedetecting steps.

In addition, an embodiment of the present disclosure further provides adevice for transmitting the synchronization signal block, which can beimplemented as all or a part of an access network device by software,hardware, or a combination of both software and hardware. The device fortransmitting the synchronization block includes a transmitting unitconfigured to implement the function of the foregoing steps 301, 304,401, 405, 501, 505, 601, 605, 701, 705 and functions related to thetransmission step.

FIG. 9 is a schematic structural diagram of a terminal according to anexemplary embodiment of the present disclosure. The terminal includes aprocessor 21, a receiver 22, a transmitter 23, a memory 24, and a bus25.

The processor 21 includes one or more processing cores, and theprocessor 21 executes various functional applications and informationprocessing by running software programs and modules.

The receiver 22 and the transmitter 23 can be implemented as onecommunication component. The communication component can be acommunication chip, which can include a receiving module, a transmittingmodule, a modem module, etc., and is configured to modulate and/ordemodulate information, and receive or send this information viawireless signals.

The memory 24 is coupled to the processor 21 via the bus 25.

The memory 24 can be configured to store software programs and modules.

The memory 24 can store at least one of the functions described by theapplication module 26. The application module 26 can include a receivingmodule 261, a determining module 262, and a detecting module 263.

The processor 21 is configured to execute the receiving module 261 toimplement the functions of the steps of receiving the synchronizationsignal block in the foregoing various method embodiments. The processor21 is configured to execute the determining module 262 to implement thesteps of determining the location of the time-frequency resource in theforegoing various method embodiments. The processor 21 is configured toexecute the detecting module 263 to implement the functions of the stepsof detecting the synchronization signal block in the foregoing variousmethod embodiments.

Moreover, the memory 24 can be implemented by any type of volatile ornon-volatile memory device, or a combination thereof, such as a staticrandom access memory (SRAM), an electrically erasable programmable readonly memory (EEPROM), an erasable programmable read only memory (EPROM),a programmable read only memory (PROM), a read only memory (ROM), amagnetic memory, a flash memory, a disk or an optical disk.

FIG. 10 is a schematic structural diagram of an access network deviceaccording to an exemplary embodiment of the present disclosure. Theaccess network device includes: a processor 21, a receiver 22, atransmitter 23, a memory 24, and a bus 25.

The processor 21 includes one or more processing cores, and theprocessor 21 executes various functional applications and informationprocessing by running software programs and modules.

The receiver 22 and the transmitter 23 can be implemented as onecommunication component. The communication component can be acommunication chip, which can include a receiving module, a transmittingmodule, a modem module, etc., and is configured to modulate and/ordemodulate information, and receive or send this information viawireless signals.

The memory 24 is coupled to the processor 21 via the bus 25.

The memory 24 can be configured to store software programs and modules.

The memory 24 can store an application module 26 as described by atleast one of the functions. The application module 26 can include atransmission module 261.

The processor 21 is configured to execute the transmission module 261 toimplement the functions of the steps of transmitting the synchronizationsignal block in the foregoing various method embodiments.

Moreover, the memory 24 can be implemented by any type of volatile ornon-volatile memory device, or a combination thereof, such as a staticrandom access memory (SRAM), an electrically erasable programmable readonly memory (EEPROM), an erasable programmable read only memory (EPROM),a programmable read only memory (PROM), a read only memory (ROM), amagnetic memory, a flash memory, a disk or an optical disk.

Those skilled in the art should appreciate that in one or more of theabove examples, the functions described in the embodiments of thepresent disclosure may be implemented in hardware, software, firmware,or any combination thereof. When the functions are implemented by thesoftware, the functions may be stored in a computer readable medium ortransmitted as one or more instructions or code on the computer readablemedium. The computer readable medium includes the computer storagemedium and the communication medium, wherein the communication mediumincludes any medium that facilitates the transmission of the computerprogram from one location to another. The storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer.

Exemplary embodiments of the present disclosure are described above, andhowever the embodiments are not intended to limit the presentdisclosure. Any modifications, equivalent substitutions, improvements,etc., which are within the spirit and scope of the present disclosure,should be included in the protection scope of the present disclosure.

What is claimed is:
 1. A terminal device, comprising: a receiverconfigured to receive a first synchronization signal block transmittedby an access network device, wherein the first synchronization signalblock comprises a physical broadcast channel (PBCH); and a processorconfigured to determine a location of a frequency resource of a secondsynchronization signal block according to preset information comprisedin the physical broadcast channel (PBCH), wherein the firstsynchronization signal block and the second synchronization signal blockcarry same information.
 2. The terminal device according to claim 1,wherein the preset information comprises a frequency domain intervalbetween the first synchronization signal block and the secondsynchronization signal block; wherein the processor is configured to:determine a frequency domain location of the second synchronizationsignal block according to a frequency domain location of the firstsynchronization signal block and the frequency domain interval betweenthe first synchronization signal block and the second synchronizationsignal block.
 3. The terminal device according to claim 1, wherein theprocessor is configured to detect the second synchronization signalblock.
 4. A terminal device, comprising: a receiver configured toreceive a first synchronization signal block transmitted by an accessnetwork device; wherein the first synchronization signal block comprisesa primary synchronization signal (PSS), a secondary synchronizationsignal (SSS) and a synchronization channel; and a processor configuredto determine a location of a time-frequency resource of a secondsynchronization signal block according to preset information comprisedin the first synchronization signal block, wherein the firstsynchronization signal block and the second synchronization signal blockare sent using a same beam.
 5. The terminal device according to claim 4,wherein the processor is configured to detect the second synchronizationsignal block.
 6. The terminal device according to claim 4, wherein thepreset information comprises: a transmission period of synchronizationsignal blocks.
 7. The terminal device according to claim 4, wherein thepreset information comprises a transmission period of a synchronizationsignal block set in which the first synchronization signal block islocated.
 8. The terminal device according to claim 7, wherein the firstsynchronization signal block set comprises at least one group ofsynchronization signal blocks.
 9. The terminal device according to claim8, wherein the processor is configured to: determine the transmissionperiod as a time domain interval between the first synchronizationsignal block and the second synchronization signal block.
 10. Theterminal device according to claim 9, wherein the time domain intervalis at least one of a number of sub-frames, number of slots, number ofmini-slots, or number of orthogonal frequency division multiplexing(OFDM) symbols.
 11. The terminal device according to claim 9, whereinthe processor is further configured to: determine a time domain locationof the second synchronization signal block according to the time domaininterval and a time domain location of the first synchronization signalblock.
 12. The terminal device according to claim 4, wherein the presetinformation comprises a first time domain index of the firstsynchronization signal block, and the first time domain index indicatesa time domain location of the first synchronization signal block. 13.The terminal device according to claim 12, wherein the first time domainindex is an index of the first synchronization signal block in asynchronization signal block set.
 14. The terminal device according toclaim 12, wherein the first time domain index is an index ofsynchronization signal block among all synchronization signal blockslocated in a radio frame, a sub-frame, or a time slot where the firstsynchronization signal block is located in.
 15. The terminal deviceaccording to claim 13, wherein the synchronization signal block setcomprises at least one group of synchronization signal blocks, and atime domain resource is a sub-frame, a time slot, a mini-slot or anorthogonal frequency division multiplexing OFDM symbol.
 16. The terminaldevice according to claim 12, wherein the processor is furtherconfigured to: perform joint detection of a first synchronization signalin the first synchronization signal block and a second synchronizationsignal in the second synchronization signal block.
 17. The terminaldevice according to claim 12, wherein the processor is furtherconfigured to: perform joint detection of a first synchronizationchannel in the first synchronization signal block and a secondsynchronization channel in the second synchronization signal block. 18.The terminal device according to claim 12, wherein the processor isconfigured to: calculate a second time domain index corresponding to thesecond synchronization signal block according to the first time domainindex and a pre-agreed index interval.
 19. The terminal device accordingto claim 18, wherein the processor is further configured to: determine atime domain location of the second synchronization signal blockaccording to the second time domain index.
 20. A network device,comprising: a transmitter configured to transmit a first synchronizationsignal block to a terminal; and wherein the transmitter is furtherconfigured to transmit a second synchronization signal block to theterminal, wherein the first synchronization signal block and the secondsynchronization signal block are sent by a same beam; wherein the firstsynchronization signal block comprises preset information, and theterminal is configured to determine a location of a time-frequencyresource of the second synchronization signal block according to thepreset information, and detect the second synchronization signal block.